中国激光, 2020, 47 (11): 1108001, 网络出版: 2020-10-23
集成量子压缩光源中MgO∶LiNbO3晶体倍频系统研究 下载: 1028次封底文章
Frequency Doubling System for Integrated Quantum Squeezed Light Source Based on MgO∶LiNbO3 Crystal
非线性光学 倍频 二次谐波 临界相位匹配 532 nm 激光 掺氧化镁铌酸锂晶体 nonlinear optics frequency doubling second harmonic generation critical phase matching 532 nm laser MgO∶LiNbO3 crystal
摘要
基于掺氧化镁铌酸锂晶体,采用临界相位匹配技术以及半整块腔型结构进行外腔倍频实验并制备了532 nm激光。对热透镜效应引起的倍频腔模式失配进行了理论分析。在较高基频光注入倍频腔时,通过重新进行模式匹配,缓解了模式失配对倍频转换效率的影响,最终可实现最大倍频转换效率为(49.3±0.45)%的倍频过程,对应输出功率为567.0 mW。通过模式清洁器改善了输出532 nm激光的光束质量并有效降低了其强度噪声,最终实现了输出功率为470 mW、光束质量因子为1.05的低噪声532 nm激光,其在分析频率1.65 MHz处达到散粒噪声极限。此倍频系统结构紧凑,输出功率稳定,可为集成量子压缩光源提供有效泵浦光场,在量子精密测量以及量子信息科学等领域中发挥重要作用。
Abstract
Based on the MgO∶LiNbO3 crystal, the critical phase matching technology and the semi-monolithic cavity structure are used to perform external cavity frequency doubling and generate 532 nm laser. The mismatch of the frequency-doubling cavity modes caused by the thermal lens effect is theoretically analyzed. When the higher fundamental frequency light is injected into the frequency-doubling cavity, the mode matching is performed again to mitigate the effect of mode mismatch on the frequency doubling conversion efficiency. Finally, the frequency doubling process with the maximum frequency doubling conversion efficiency of (49.3±0.45)% is achieved and the corresponding output power is 567.0 mW. Furthermore, the model cleaner can not only improve the 532 nm laser beam quality but also reduce the intensity noise to realize the output power of 470 mW and the beam quality factor of 1.05 for the low-noise green laser, whose shot noise limit is reached at an analysis frequency of 1.65 MHz. The whole frequency doubling system possesses a compact structure, a stable output power, and can supply an effective pump field for the quantum squeezed light source, and thus it can play an important role in quantum precision measurement and quantum information fields.
田宇航, 王俊萍, 杨文海, 田龙, 王雅君, 郑耀辉. 集成量子压缩光源中MgO∶LiNbO3晶体倍频系统研究[J]. 中国激光, 2020, 47(11): 1108001. Tian Yuhang, Wang Junping, Yang Wenhai, Tian Long, Wang Yajun, Zheng Yaohui. Frequency Doubling System for Integrated Quantum Squeezed Light Source Based on MgO∶LiNbO3 Crystal[J]. Chinese Journal of Lasers, 2020, 47(11): 1108001.